A question I am asked frequently about online learning is: "Schools aren't just responsible for learning. They are responsible for doing a socialization job. Won't online learning hurt that?"
There are also many answers to this -- and, I'd like to add, many other jobs for which schools are held responsible, too, that online learning in its most narrow form may not cover.
First, we should be honest and acknowledge that the socialization in our schools is not always a good thing and is certainly not always good for every student. Many a parent has said to me (paraphrased): "Online learning sounds great. The socialization that actually occurs in schools because of peer influence doesn't help my child at all; in fact, it's had a really negative and destructive influence!" Parents may mean different things by the statement, but we see forms of the sentiment all the time. Sometimes children are afraid to ask questions in classrooms; afraid to excel and be deemed "un-cool"; afraid to come to school because of bullying, and on and on. Online learning for many might provide the needed shelter to allow them to excel.
I also think that socialization is one of the dimensions where online learning will continue to improve. The interaction between teacher and student and student to other students in the first versions of online learning was clunky; the best didn't come close to replicating a high-quality in-class experience. But, just like any technology, thanks to the work of players like Elluminate, this experience is predictably improving. As many have also written, many full-time online schools have added elements to foster student social interaction like field trips and the like (see the Keeping Pace with K-12 Online Learning report for example). And online interaction is increasingly a part of today's society; students in online programs can theoretically interact with people from anywhere in the world, not just their locality, which is exciting.
In addition, online learning is increasingly becoming less and less of a distance phenomenon as hybrid- or blended-learning -- which has a bricks-and-mortar component to it -- is growing faster than the distance side of the equation, according to this Sloan Consortium report. This doesn't surprise me. Because of the custodial job that schools need to fill for many families to the job of socialization, there are a lot of reasons to suggest that students will still go to facilities of some sort for their education -- even if the platform for much of what they will do academically is online.
Finally, a recent survey has come out on the topic that you can read here. The results suggest that typical, mainstream students enrolled in full-time, online public schools are either superior to or not significantly different from students enrolled in traditional public schools with respect to their socialization. There are some reasons for caution on the survey that the authors acknowledge -- the design is post-test only and because those in these schools are there by choice it wasn't possible to "design a random assignment control group experiment" -- so drawing a causal inference and saying enrollment in an online school results in better socialization would be dangerous.
But the study is important in one important respect even if it can't be considered conclusive as it shows that there probably aren't negative social characteristics or problem behaviors associated with participation in online public schools per se. If the end goal is to have children who are well socialized, that's an important finding.